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[CIFS] Migrate from prefixpath logic

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Now we point superblock to a server share root and set a root dentry
appropriately. This let us share superblock between mounts like
//server/sharename/foo/bar and //server/sharename/foo further.

Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru>

Signed-off-by: Steve French <sfrench@us.ibm.com>
This commit is contained in:
Steve French
2011-05-27 03:50:55 +00:00
parent 641a58d66d
commit f87d39d951
7 changed files with 189 additions and 148 deletions
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101
fs/cifs/cifsfs.c
View File

@@ -415,8 +415,6 @@ cifs_show_options(struct seq_file *s, struct vfsmount *m)
seq_printf(s, ",nocase");
if (tcon->retry)
seq_printf(s, ",hard");
if (cifs_sb->prepath)
seq_printf(s, ",prepath=%s", cifs_sb->prepath);
if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_POSIX_PATHS)
seq_printf(s, ",posixpaths");
if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SET_UID)
@@ -530,6 +528,100 @@ static const struct super_operations cifs_super_ops = {
#endif
};
/*
* Get root dentry from superblock according to prefix path mount option.
* Return dentry with refcount + 1 on success and NULL otherwise.
*/
static struct dentry *
cifs_get_root(struct smb_vol *vol, struct super_block *sb)
{
int xid, rc;
struct inode *inode;
struct qstr name;
struct dentry *dparent = NULL, *dchild = NULL, *alias;
struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
unsigned int i, full_len, len;
char *full_path = NULL, *pstart;
char sep;
full_path = cifs_build_path_to_root(vol, cifs_sb,
cifs_sb_master_tcon(cifs_sb));
if (full_path == NULL)
return NULL;
cFYI(1, "Get root dentry for %s", full_path);
xid = GetXid();
sep = CIFS_DIR_SEP(cifs_sb);
dparent = dget(sb->s_root);
full_len = strlen(full_path);
full_path[full_len] = sep;
pstart = full_path + 1;
for (i = 1, len = 0; i <= full_len; i++) {
if (full_path[i] != sep || !len) {
len++;
continue;
}
full_path[i] = 0;
cFYI(1, "get dentry for %s", pstart);
name.name = pstart;
name.len = len;
name.hash = full_name_hash(pstart, len);
dchild = d_lookup(dparent, &name);
if (dchild == NULL) {
cFYI(1, "not exists");
dchild = d_alloc(dparent, &name);
if (dchild == NULL) {
dput(dparent);
dparent = NULL;
goto out;
}
}
cFYI(1, "get inode");
if (dchild->d_inode == NULL) {
cFYI(1, "not exists");
inode = NULL;
if (cifs_sb_master_tcon(CIFS_SB(sb))->unix_ext)
rc = cifs_get_inode_info_unix(&inode, full_path,
sb, xid);
else
rc = cifs_get_inode_info(&inode, full_path,
NULL, sb, xid, NULL);
if (rc) {
dput(dchild);
dput(dparent);
dparent = NULL;
goto out;
}
alias = d_materialise_unique(dchild, inode);
if (alias != NULL) {
dput(dchild);
if (IS_ERR(alias)) {
dput(dparent);
dparent = NULL;
goto out;
}
dchild = alias;
}
}
cFYI(1, "parent %p, child %p", dparent, dchild);
dput(dparent);
dparent = dchild;
len = 0;
pstart = full_path + i + 1;
full_path[i] = sep;
}
out:
_FreeXid(xid);
kfree(full_path);
return dparent;
}
static struct dentry *
cifs_do_mount(struct file_system_type *fs_type,
int flags, const char *dev_name, void *data)
@@ -585,7 +677,10 @@ cifs_do_mount(struct file_system_type *fs_type,
sb->s_flags |= MS_ACTIVE;
root = dget(sb->s_root);
root = cifs_get_root(volume_info, sb);
if (root == NULL)
goto out_super;
cFYI(1, "dentry root is: %p", root);
goto out;
out_super: